1. Field of the Invention
The present invention relates to a display and, more particularly, to a display having a reflective region and a transmissive region.
2. Description of the Background Art
There has been conventionally known a transflective type liquid crystal display having two functions of a transmissive type, in which a light beam incident into a liquid crystal layer is allowed to pass only in one direction, and a reflective type, in which a light beam incident into a liquid crystal layer is reflected. Such a transflective type liquid crystal display is disclosed in, for example, Japanese Patent Application Publication No. 2002-98951.
FIG. 17 is a plan view showing the structure of a transflective type liquid crystal display having a projecting insulating film (i.e., a planarization film) in the prior art; and FIG. 18 is a cross-sectional view taken along a line 190—190, showing the display in the prior art shown in FIG. 17.
As shown in FIG. 18, in the transflective type liquid crystal display in the prior art, an active layer 102 is formed in a predetermined region corresponding to a reflective region 160a on a glass substrate 101 having a buffer layer 101a formed thereon. In the active layer 102, a source region 102a and a drain region 102b are formed to hold a channel region 102c therebetween. Furthermore, a gate electrode 104 is formed on the channel region 102c having a gate insulating film 103 interposed therebetween. Moreover, an auxiliary capacitance line 105 is formed in a predetermined region on the gate insulating film 103 corresponding to the reflective region 160a. An auxiliary capacitance consists of an auxiliary capacitance region 102d of the active layer 102, the gate insulating film 103 and the auxiliary capacitance line 105. As shown in FIG. 17, the gate electrode 104 is connected to a gate line 104a. 
As shown in FIG. 18, an interlayer insulating film 106 having contact holes 106a and 106b is formed to cover a thin film transistor and the auxiliary capacitance. A source electrode 107 and a drain electrode 108 are formed on the interlayer insulating film 106 via the contact holes 106a and 106b in such a manner as to be electrically connected to the source region 102a and the drain region 102b, respectively. As shown in FIG. 17, the drain electrode 108 is connected to a drain line 108a. As shown in FIG. 18, a planarization film 109 having openings 109a and 109b is formed in a projecting cross section on the interlayer insulating film 106. As shown in FIG. 17, the opening 109a is formed to surround a transmissive region 160b while the opening 109b is formed in a region corresponding to the source electrode 107. A side end 104b of the gate line 104a and a side end 105a of the auxiliary capacitance line 105 are formed in a region under the planarization film 109 separated with a predetermined interval from a region in which a side end 109c of the opening 109a is located.
Additionally, as shown in FIG. 18, a reflective electrode 110 is formed in a region corresponding to the reflective region 160a in such a manner as to be electrically connected to the source electrode 107 via the opening 109b and extend along the upper surface of the planarization film 109 and the side surface of the opening 109a. Furthermore, an opening 110a is formed in a region corresponding to the transmissive region 160b in the reflective electrode 110. A transparent electrode 111 is formed on the interlayer insulating film 106 located in the reflective electrode 110 and the opening 110a. The transparent electrode 111 and the reflective electrode 110 constitute a pixel electrode.
Moreover, a substrate (i.e., an opposite substrate) 112 is disposed at a position opposite to the substrate 101. A color filter 113, which exhibits each color of red, green and blue, is formed on the substrate 112, and further, a black matrix 114 is embedded in a space defined between the color filters 113. An opposite electrode 115 is formed on the color filter 113 and the black matrix 114. An aligning film, not shown, is formed on each of the transparent electrode 111 and the opposite electrode 115. A liquid crystal layer 116 is filled between the two aligning films.
When the planarization film 109 is exposed to a light beam in the case where the opening 109a is formed in the region corresponding to the transmissive region 160b by using photolithography in the above-described transflective type liquid crystal display in the prior art, a light beam transmitting the substrate 101 may be turbulently reflected on a substrate stage, not shown, of an exposing device. In this case, since the region in which the side end 109c is formed at the opening 109a is irradiated with the turbulently reflected light beam during the exposure, a portion, into which the turbulently reflected light beam enters, may be accidentally removed at the time of development. Consequently, as shown in FIG. 17, there has caused an inconvenience that a recess 109d due to the turbulently reflected light beam is formed at the side end 109c of the opening 109a, and further, that a portion of the reflective electrode 110 formed on the side end 109c of the planarization film 109 also is recessed. As a result, an image reflecting the recess of the reflective electrode 110 is displayed on a screen, thereby raising a problem of degradation of a displaying quality.